Eliasson A, Bernander R, Nordström K
Department of Microbiology, Uppsala University, Sweden.
Mol Microbiol. 1996 Jun;20(5):1025-32. doi: 10.1111/j.1365-2958.1996.tb02543.x.
We have constructed intP1 and intFs strains of Escherichia coli in which the basic replicons of either plasmid P1 or plasmid F (oriS) were integrated into an inactivated oriC, such that chromosome replication is controlled by the integrated plasmid replicon. In this study, we have further analysed these strains, and density-shift experiments revealed that chromosome replication occurred randomly during the cell cycle. Flow-cytometry analyses of exponentially growing populations supported this conclusion, and also showed that the DNA/mass ratio of the strains decreased with increasing growth rate. Flow cytometry of exponentially growing cultures treated with rifampicin demonstrated that initiation of replication was uncoordinated in cells containing multiple replication origins.
我们构建了大肠杆菌的intP1和intFs菌株，其中质粒P1或质粒F的基本复制子（oriS）被整合到失活的oriC中，从而使染色体复制由整合的质粒复制子控制。在本研究中，我们进一步分析了这些菌株，密度转移实验表明染色体复制在细胞周期中随机发生。对指数生长群体的流式细胞术分析支持了这一结论，并且还表明这些菌株的DNA/质量比随生长速率的增加而降低。用利福平处理的指数生长培养物的流式细胞术表明，在含有多个复制起点的细胞中，复制起始是不协调的。
